Airspace ClassesTypes of Airspaces and How Are They Defined
The National Airspace System is a complex layout of several different layers of airspace categorized for specific need, function, or level of control. When becoming a pilot it is very important to become well versed in the functions and regulations of each individual airspace. There are two main categories of airspaces: regulatory and nonregulatory. Within those two categories exist four types:
Controlled and Uncontrolled Airspaces Types of Airspaces
Controlled and uncontrolled airspaces are the ones you will spend most of your time flying within as a pilot. Controlled airspace consists of five tiers beginning with most restrictive to least restrictive: Class Alpha (A), Class Bravo (B), Class Charlie (C), Class Delta (D), and Class Echo (E).
Class A airspace generally begins from 18,000 feet mean sea level up to and including 60,000 feet. Operations in Class A are generally conducted under Instrument Flight Rules and primarily used by higher performance aircraft, airline and cargo operators, etc.
Class B Airspace:
Class B airspace utilizes the space surrounding the nation’s busiest airports and begins from the surface to 10,000 feet MSL. Class B is made up of several layers of varying sizes and shapes, is individually tailored for the needs of the airspace, and often resembles an upside-down wedding cake, with the airspace widening as altitude is increased. All aircraft are required to obtain a clearance from ATC and follow their guidance to operate within or through Class B airspace.
Class C Airspace:
Class C surrounds busy airports that are not quite as busy as Class B airports. It is also made up of layers tailored to the needs of the airspace but is not as elaborate as Class B. In Class C you will generally find a 5 nautical mile inner ring from the surface to 4,000 feet, and a 10 nautical mile outer ring from 1,200 to 4,000 feet above the airport elevation. An aircraft does not need specific clearance into the Charlie airspace, but two-way radio communications with the ATC facility and their provision of air traffic services must be obtained prior to entering, and maintained while inside the airspace.
Class D Airspace:
Moving on to lesser and lesser restricted airspace, the Class D airspace exists around airports that still have an operating control tower but are not as busy as the Class C airports. Generally beginning from the surface to 2,500 feet above airport elevation, the shape of Class D airspace is individually tailored but exists as just one layer, rather than having varying shapes stacked on top of each other. Two-way communication must be made and maintained prior to entering and while operating within the Class D airspace.
Class E Airspace:
Class E airspace is any controlled airspace not classified as the aforementioned airspaces surrounding airports. Most of the airspace in the United States is designated Class E airspace. The level of control within Class E airspace is meant for air traffic operating on Instrument Flight Rules, while aircraft flying under Visual Flight Rules usually have the freedom to move throughout the airspace as they wish. Where Class E begins and ends can be complex, but in most areas, Class E airspace begins at 1,200, while others may have Class E beginning at the surface or at 700 above ground level (AGL). The airspace extends up to but not including 18,000 feet MSL, and also excluding any other overlying airspace. Class E begins again above 60,000 feet. There are areas where the base of Class E is depicted on the sectional as starting at different altitudes than standard, such as offshore surrounding the contiguous United States.
Class G Airspace:
Uncontrolled airspace is known as Class Golf (G), and is the portion of airspace not designated as any of the previous airspaces. Class G extends from the surface to the base of the overlying Class E airspace. Pilots can operate as they choose, barring any regulatory requirements restricting their movement, such as low altitude aerobatics or conducting activities that may pose a hazard to people or objects on the ground. Most of the airports in the United States are uncontrolled, meaning they have no control tower and pilots must coordinate their own airport operations by utilizing onboard radio if equipped.
Some areas of the National Airspace System have been designated as Special Use Airspace. Certain activities must be confined to special use airspace and limitations may be imposed on aircraft that are not part of those activities. These areas are Prohibited, Restricted, Warning, Military Operations Areas (MOAs), Alert areas, and Controlled Firing Areas (CFAs). Most of these areas are depicted on pilot sectional charts with Controlled Firing Areas being the exception.
Prohibited areas are off limits to aircraft and are heavily protected for security and national welfare reasons.
Restricted areas may contain operations that are hazardous to nonparticipating aircraft, such as artillery firing, aerial gunnery, or guided missiles. It may be possible to transit restricted areas that are not in use, but confirmation of inactivity with the controlling authority is required.
Warning areas extend from 3 nautical miles outward from the coast of the United States and are similar to restricted areas with regard to hazards for non-participating aircraft.
Military Operations Areas (MOAs) separate certain military training activities from aircraft operating under Instrument Flight Rules. Some IFR traffic may be cleared through is separation can be provided by ATC. Traffic flying under Visual Flight Rules may transit the MOA but acute awareness must be maintained. Often it is better to just avoid the MOA if at all possible.
Alert areas show pilots where a high volume of pilot training or unusual aerial activity generally occurs. Pilots should be cautious when flying in alert areas and all pilots within the Alert area are equally responsible for collision avoidance.
Controlled Firing Areas (CFAs), as mentioned, are not shown on pilot sectional charts. Activities that could be hazardous to nonparticipating aircraft occur within these areas. It is not required for pilots to know where they are because all activities are suspended when a spotter aircraft, radar, or ground lookout position indicates an aircraft may be approaching the area. Pilots do not need to alter their flight path through these areas.
There are other airspace areas pilots will become familiar with as they progress through their training. For example, a Temporary Flight Restriction (TFR) is an area that temporarily restricts or limits the type of flight activities that may occur within the area. These may be created for potential hazard areas, aerial firefighting or disaster relief efforts, limit the amount of aerial activity over an area or event that may generate a high level of interest such as sporting events or sightseeing destinations, movement of VIPs like the President or Vice President, space launch or recovery operations, etc. Other airspaces of interest may be military training routes, parachute jump aircraft operations, national security areas (NSA), and Air Defense Identification Zones.
Why Is It Important for Pilots to Learn About the Airspaces?
It is in the best interest of every pilot to become familiar with airspace and the limitations or regulations associated with each individual airspace. For example, each class of airspace has their own weather minimums when flying on Visual Flight Rules. Class A is IFR only and not a factor, but Class B, C, D, and E each have their own complex set of rules with regard to visibility and cloud clearance required.
Pilots spend hours studying these weather minimums and other regulations associated with the individual airspaces in order to ensure safety of flight and avoiding finding themselves explaining a deviance from a regulation to the FAA.
As an example, if a pilot accidentally enters a Class B airspace without explicit clearance to do so they could potentially lose their pilot privileges indefinitely. Flying through a Prohibited area or TFR could result in being intercepted by military fighter aircraft, certainly not a situation in which a civilian pilot wants to find themselves. On the other hand, a VFR pilot unfamiliar with the regulations concerning Military Operations Areas may some day find themselves planning a cross country flight path hours out of the way around a massive MOA, even though they legally are allowed to fly through it, and when exercising additional caution, are likely perfectly safe in doing so. Of course, if it is reasonable to avoid it, some additional flight time to go around may be worth the extra boost in safety.
The type of airspace in which a flight school is located is something to be considered when choosing a training center. There are some distinct advantages and disadvantages for each airport environment. ATP Flight School has no training locations inside of Class B, but does have locations at Class C, Class D, and Class G airports. Operating out of a Class C airport provides the opportunity to learn busy airport operations. This environment requires pilots to gain excellent proficiency in radio communications and a heightened sense of situational awareness as the dynamics of busy airspace become evident. Pilots that learn in busy airport environments will generally process information faster and work more efficiently in the cockpit. Learning to fly in large airport environments may shape pilots preparedness for their professional careers. The downside to large, busy airports is the prevalence of airport delays, extended periods of time spent on the ground taxiing to and from the large runways, the potential for deviating from instructions by air traffic control, and likelihood of being overwhelmed from operating around much larger, faster aircraft in an already stressful environment, especially for brand new pilots.
On the other hand, Class D and Class G airports usually provide quick access to the runway environment and very few airport delays. More time is spent actually flying and practicing rather than taxiing or waiting for takeoff clearance behind multiple arrivals. Instructions from air traffic control are generally easier to follow and the more laid-back environment provides a much better environment for learning the fundamentals. However, pilots that have limited experience in large airport operations generally have an overwhelming anxiety about flying to these airports, struggle to keep up with the fast pace, and have often found themselves in dangerous situations when underestimating just how stressful the environment can be, or overestimating their own skills in dealing with task saturation. Of course, this challenge can be overcome by flying to the large airports nearby to gain exposure while benefiting from the advantages of the smaller airport operations for every day flying.